And the crisis deepened last night after it was claimed that Mr Werritty, his ex-flatmate and best man at his wedding, ran a right-wing charity from his office as an MP.

Mr Werritty was reported to have used Fox’s room at Portcullis House as the headquarters of the charity Atlantic Bridge which Fox founded to strengthen US/UK ties.

But the charity of which Baroness Thatcher was said to be honorary patron and George Osborne, William Hague and Michael Gove reported to have served on its board, has been wound up amid criticism that it was too political for charitable status.

MEETING

Dr Fox, 50, met Mr Werritty at the MoD 14 times in 16 months, and critics allege the friendship is a breach of national security.

In Sri Lanka Mr Werritty gave out business cards describing himself as an “adviser to Rt Hon Dr Liam Fox MP” – raising questions over whether he is using his links to Dr Fox to profit financially.

Mr Werritty ran a defence company while Dr Fox was shadow defence secretary and he was involved in a health company when the MP was shadow health secretary.

Their friendship dates back 14 years. They shared a flat before the MP married Jesme Baird in 2005.

Mr Werritty has accompanied Dr Fox on trips to the Middle East, Israel and the US and a cloud hangs over a meeting he brokered between Dr Fox and the MoD’s private equity partner Porton Capital in Dubai.

When details emerged of their links, Dr Fox told Parliament: “Mr Werritty is not an MoD employee and has not travelled on official visits.”

But when the Sri Lanka photo emerged, the MoD said Mr Werritty wasn’t part of the delegation and “did not attend official meetings”, adding that Mr Werritty’s MoD meetings with Dr Fox concerned “private matters”.